High polarization and fast modulation speed of dual wavelengths electroluminescence from semipolar (20-21) micro light-emitting diodes with indium tin oxide surface grating

摘要

We present highly polarized dual wavelength semipolar InGaN micro-light-emitting diodes (μLEDs) by combining an indium tin oxide (ITO) surface grating and Al-coated dual-color surface plasmons (DSPs). The ITO grating DSPs enable a significant enhancement of the polarization ratio (PR) from electrically driven semipolar (20-21) μLEDs with dual emission wavelengths: the overall PR was increased by 1.7-folds and the output power was enhanced by 78% as compared to the conventional semipolar μLEDs at an injection current density of 100 A/cm~2. Moreover, a high 3dB modulation bandwidth of 612 MHz is achieved at ～1.4kA/cm~2 in a visible-light communication (VLC) system, suggesting a near 1.24 Gbit/s under a non-return-to-zero on-off keying modulation scheme. This design marks significant progress in developing polarized μLEDs with potential applications in various fields, such as displays and VLC.